Concerns have been raised about Physical Education becoming an exam subject when some schools do not have the required facilities.
The Department of Education announced last year that PE is to be introduced as an exam subject in a small number of schools, beginning this term.
ASTI Assistant General Secretary Moira Leydon told the Oireachtas Joint Committee on Education and Skills that when the new science syllabus was introduced a number of schools received derogation to postpone introducing the syllabus, because they did not have the facilities to proceed.
"I know for a fact that a number of schools didn't apply for the new Leaving Cert PE examination for the simple reason that could not provide the eight optional physical activities to meet the requirements of the programme," she said.
She asked that when curriculum change is considered that we also look at "bricks and mortar" and where we are going to it.
Issues around more space for school students, better school maintenance, and the bulge in school enrolments were also raised at the hearing.
A Concerned Parents Group, from Our Lady's Grove Primary School in Goatstown, Dublin, urged the Department of Education and Skills to examine all zoning and planning applications for lands bordering schools.
Lisa Ryan said that sports facilities and open spaces are crucial for the physical and mental health of students, and "this should not only be available to children attending private schools in Dublin."
Karen Jordan, the principal of St Catherine's National School, Donore Avenue, said the Department of Education is obliged to ensure that schools have the adequate environment and space to implement active learning, which is current best practice.
Seamus Mulconry, of the Catholic Primary Schools Management Association, spoke about 42 oversubscribed schools.
In particular, one in Greystones, Co Wicklow, where a principal recently discovered that there will be 700 new houses beside the school.
He said the problem is not going to go away, rather that the demographic bulge is going to increase.
Paul Hogan, a senior advisor with the Department of Housing, Planning and Local Government, said the minister is procluded from getting involved in planning cases.
He said the local authorities rezone the land and it is their responsibility.
On the impact a lack of space can have on students, the principal of St Catherine's National School in Dublin, Karen Jordan said: "Our class sizes can be detrimental to the roll out of Aistear, any kind of new maths curriculum, any new oral language or any other curriculum.
"On the department's own website the average classroom size is 80 square metres, our biggest is 66 square metres and our smallest, housing 25 children, is 36 square metres."
Only 50% of catholic primary schools have full sized PE halls, according to Mr Mulcrony.
"72% of those schools had those PE halls fully or partly funded by the school, so this is very important, because we have 64 new schools taking it as a subject."
Ms Ryan said: "It's the poor children who suffer because there aren't sports facilities being offered on site in the school, whereas the middle class kids are being driven to clubs or to other places."